DPF Regeneration & Diesel Particulate Filters

A Diesel Particulate Filter (DPF) is designed to capture up to 80% of soot and harmful emissions from diesel engines. Over time, these filters can become clogged, causing warning lights and limp mode. Regular DPF maintenance ensures your engine runs efficiently and avoids costly repairs.

DPF regeneration is the process of burning soot trapped in the filter. There are two main types:

• Passive Regeneration: Happens automatically at high exhaust temperatures, typically during motorway drives.
• Active Regeneration: Controlled by the ECU using post-combustion fuel injection to raise exhaust temperature when passive conditions are not met.

• Increased fuel consumption
• Louder engine sounds or higher RPM
• Hot or acrid smell from the exhaust
• Faster engine cooling fan operation
• Start/Stop temporarily disabled

• Excessive soot and ash accumulation
• Oil contamination with diesel
• Premature DPF replacement or costly repairs
• Risk of engine damage if ignored

• Short journeys preventing high exhaust temperature
• Low fuel levels preventing ECU recognition of regeneration
• Incorrect engine oil type (must be low ash & sulfur)
• Faulty EGR valves or engine management issues
• Low additive tank fluid for vehicles with additives